Somewhere beneath the surface of Ballyshonock Reservoir in County Waterford, a cluster of prehistoric cooking sites lies submerged, sealed under water that has covered the valley since the reservoir was created. Seven of them were recorded in the same narrow valley, which is a notably high concentration for a single stream corridor.

The sites are fulachta fiadh, a term for the burnt mounds that are among the most common prehistoric monuments in Ireland. The typical fulacht fiadh consists of a horseshoe-shaped mound of fire-cracked stones and charcoal, usually beside a water source, formed by the repeated process of heating stones in a fire and dropping them into a water-filled trough to bring it to the boil. They date most commonly to the Bronze Age, roughly 1500 to 500 BC, though examples span a wider range. The seven recorded at Ballyshonock sat along a north-south stream valley, a setting entirely typical of the monument type, since running water was essential to the process. The concentration of seven sites in one valley suggests the location was returned to repeatedly over time, perhaps across generations.